Using Pneumatic Finger Gripper Link for Automated CNC Machine Tending of Aluminum Parts Operation Process and Efficiency

This is Wang, a technician from CNC workshop #3. I previously introduced that pneumatic finger gripper. Today, I'll detail how we used it to retrofit a production line for automated loading and unloading of aluminum end caps.

I. Case Background:

This line previously relied entirely on manual operation. One worker manned two machines, which was labor-intensive, created a slow cycle time, and posed safety risks. The part being machined was an aluminum end cap, approximately 120mm in diameter, with a raw blank weighing about 2.5kg.

II. The Process:

1. System Integration: We selected the 80mm opening pneumatic gripper link, mounting it to a 6-axis robot arm via an adapter flange. The pneumatic lines were connected to the machine's existing valve manifold, controlled collaboratively by the CNC's PLC and the robot's controller.
2. Gripping & Positioning: I designed and machined a pair of V-shaped custom fingers for the gripper, perfectly contouring the workpiece's outer diameter. The robot first moves to the material rack, the gripper descends, positions accurately, and closes to firmly grip the raw blank.
3. Loading/Unloading Operation: 
   • Loading: The robot carries the blank to the CNC machining center door and waits for it to open. It then precisely inserts the workpiece above the chuck. The chuck closes automatically, the gripper releases, and the robot retracts.
   • Machining: The machine door closes, and machining begins.
   • Unloading: After machining completes, the door reopens. The robot moves in, the gripper grabs the finished part, the chuck opens, and the robot extracts the part and places it onto a conveyor belt.
   • Simultaneously, the robot's same gripper immediately moves to pick up a new blank, preparing for the next cycle.
4. Cycle Time Control: The entire process—from pick, load, wait, unload, to place—has a consistent cycle time of 45 seconds per part. The gripper's fast response and high repeat accuracy were crucial, ensuring the part was placed into the chuck accurately and without error every time.

III. Benefits Realized:

The results after the retrofit were immediate:

• Increased Efficiency: Achieved true 24/7 uninterrupted production. Shift output increased by over 30%.
• Stable Quality: Eliminated variability from manual operation. Consistent part placement resulted in more consistent machining quality.
• Improved Safety: Operators now only need to periodically replenish the material rack and perform rounds, keeping them far from the machine's moving parts, significantly enhancing safety.
• Reduced Costs: One operator can manage multiple machines in a cell, leading to substantial long-term labor cost reduction.

Throughout this process, the gripper link performed like the robot's dependable iron hand—hardworking, precise, and durable. It was the key component that made this automation retrofit a success.